BRAIN ACTIVITY ASSESSED WITH PET DURING RECALL OF WORD LISTS AND NARRATIVES

THIS study investigated the functional neuroanatomy involved in retrie val of structured versus unstructured verbal information. We compared cerebral blood flow using PET with the [O-15]water method while subjec ts engaged in recall of novel and practised narratives and lists of un related words. Left orbital frontal cortex was activated during recall of both novel and practised unrelated words. Right parietal cortex wa s relatively more active during recall of the novel word list. Right o rbital frontal cortex and anterior cingulate were relatively more acti ve during recall of the practised but not the novel word list. These r esults are consistent with the role of left orbital frontal cortex in retrieval of unstructured verbal information. Right orbital frontal ac tivity suggests that cognitive strategies may be involved in retrieval of well-practised words.